This study used Focus Group to analyze user requirements for user interface so as to understand what capabilities of the Collaborative Problem Solving (CPS) Instructional Platform were expected by users. After 12 focus group interviews, the following four functions had been identified as essential to the CPS Instructional Platform: CPS instructional models, instructional resources database, evaluation system, and instructional plan sharing. The user interface for the CPS Instructional Platform were designed accordingly. After programmers of the integrated project had completed system development based on the design, the study was proceeded by usability evaluation of user interface of the CPS Instructional Platform. As for the satisfaction survey, 33 users were chosen based on purposive sampling. In the Likert Scale of five levels, the average score of this system was 4.1 by the testers. And, it indicated that most users were satisfied with the system user interface design and functions.